Strange Oil Problem - F650

[SteveT]

Hi all.

Friends 1993 F650's oil pressure light came on and stayed on today. Looked in the top oil tank (frame via the filler hole) - no oil visible. Bike hasn't burnt any oil (clean plugs) or lost any (no wet sump or overnight oil stains).

Put a litre of oil in (oil visible, just), ran bike, light goes off as per normal then pops back on. Flickered on & off for a very short while then stayed on. Looked in oil tank - no oil visible.

My thinking is that the scavenger pump is either not working or blocked, thus not pumping oil back to the header tank.

He's away to drop the sump plug (and expecting slightly more oil than normal to pour out Smile ) and let me know what he finds.

Has anyone had this problem before?

If so, what was the problem and the subsequent cure?

Thanks for reading this

 

[John Armstrong]

If the engine had no oil in it then 1 litre will only reduce the problem. Need to drain the oil and refill with the correct amount. And hope the engine isn't trashed and all it was, was a failing oil pressure switch.

Have you had a look here: http://faq.f650.com/

 

[SteveT]

Thanks for the prompt reply John.

Been to the Chain Gang FAQ pages and can't find the above problem there.

There has to be oil in the engine cos none has been burnt or has leaked out. It's all just swilling around in the sump (this is my assumption as I'm still waiting to hear from my mate once he's removed the sump plug )

 

[John Armstrong]

Well if the oil is in the sump, that'd make the pump as a suspect. Unless there's a pipe to from the pump that's disconnected, or is blocked.

 

[Flipfly]

Before doing anything drastic, change the oil pressure switch, thay are a regular failure.

The tank often looks empty on mine, the 650 is a pain in th earse to check the oil on

Worth changing as they are cheap and if the old one turns out to be working ok, he'll be needing a new one soon

Mine flickered on and off for a while, then came on all the time. Checked oil, topped up, still a problem. Changed pressure switch and was all sorted. Gave her a new set of filters and when I took the ol filter off the airbox was full off oil, so I'd obviously overfilled it

 

[SteveT]

Sump plug removed and 4.5 litres of oil came out - none in the frame tank!

Before sump plug pulled, engine run briefly with oil filler cap removed. Oil observed being pumped back into the frame tank and oil pressure light went out as normal.

I still think there is a pumping problem, but there is evidence of rubber contamination in the sump oil, so maybe an oil pick up pipe or feed pipe is getting blocked when suction starts from the oil pump. Not sure where to start looking though.

This could take a while, me thinks!

Thanks for the replies guys,

Steve T

 

[John Armstrong]

They haven't pressure washed the bike lately have they?

 

[SteveT]

John,

Not as far as I'm aware - are you guessing that pressure washing might have jiggered the pressure switch?

 

[John Armstrong]

John,

Not as far as I'm aware - are you guessing that pressure washing might have jiggered the pressure switch?

It's a well known way of causing a number of warning light type problems, certainly "works" on the 1150

 

[Spout]

Does your mate rev the engine before he switches off?
This will empty the tank briefly as there is a delay between the feed and return pumps. Leaving the engine to idle for 30 seconds should return the level.

 

[Beemerboff]

On my GS the oil left the header tank and didnt come back until it was good and hot.

So on a gentle run on a cold icy day the header tank was always empty.

As the handbook said that to check the oil level you had to leave the engine running until the cooling fan cut in before checking the level this didn't surprise me.

So perhaps your friend should have a read of the book before pouring oil in.

Problem he has now is that the drive to the oil/water pumps is made of some sort or black plastic, and it has been known to have been damaged by this sort of thing.

There may also be a problem with the thermostatic valve/ whatever which controls the oil return to the header.

If it was me I would have an expert check it out, but dont ask me where to find one- my BMW agent didnt employ any.

 

[Pathologic]

Flipfly is right

Try replacing the pressure sensor first. You can get them trip from any crapo car shop. Less than a fiver. Got to be the first step.

Sorted PhysioJo's bike out in minutes.

Regards,

Path.

 

[SteveT]

Update - oil pressure switch replaced, fresh oil put into frame tank - start engine - oil light goes out - then starts to come on, go off, come on again intermittently. Engine only run for less than a minute in case of causing internal damage. Frame tank still had oil in it this time (oil filler cap not left off too allow observation of oil return, so don't know if it's pumping it back from the sump to the frame tank).
Thinking of trying to crack off the frame tank filter and see if there is any crud built up on that, but will need a new pipe before thats done, as it's the original 1993 pipe thats still fitted (and it's un-suprisingly age perished).

Thanks for keeping the suggestions coming - will try and find a trained BMW type technician, but like in Aus, there don't seem to be too many around

SteveT

 

[Beemerboff]

Sounds like the drive to the pump is stuffed.

The water pump is on the other end of the shaft from the oil pump , so it should be possible to check by turning the water pump impeller, it should feeL good and solid with just a tiny bit play.

I think the crankcases have to be split to change the drive gear,but I am open to correction on that - it was just about the only thing that didnt fail on my GS